Lamp-base assembly

ABSTRACT

A lamp-base assembly for a tubular lamp bent into a U-shaped configuration in which the bases on the ends of the lamp are connected to one another by a rod.

United States Patent Marcellus N. Gilbert, Jr. Lynnfield, Mass.

June 24, 1968 May 18, 1971 Sylvania Electric Products, Inc.

lnventor Appl. No. Filed Patented Assignee LAMP-BASE ASSEMBLY 4 Claims, 3 Drawing Figs.

US. Cl 339/144,

313/318 Int. Cl 1101: 13/60 FieldoiSearch 313/318,

Primary ExaminerRichard E. Moore AttarneysNorman J. OMalley and Joseph C. Ryan ABSTRACT: A lamp-base assembly for a tubular lamp bent into a U-shaped configuration in which the bases on the ends of the lamp are connected to one another by a rod.

PATENTEflnmslsn $579,174

INVENTOR MARCELLUS N. GILBERT JR.

ATTORNEY I LAhIPfBASE ASSEMBLY This invention relates to the manufacture of elongated, linear light sources and more particularly to the manufacture of fluorescent lamps.

Generally speaking, fluorescent lamps may be viewed as being essentially linear light sources as compared to incandescent lamps which'are essentially point sources. Thus, it is not surprising to find that lighting fixtures for fluorescent lamps are generally rectangular in shape and somewhat greater in length than width. Although this general geometry of fluorescent lighting fixtures has proven tobe reasonably satisfactory in most installations calling for this type of light source, such is not always the case. For example, there are circumstances where a square lighting fixture would be more desirable, and to meet this need it has been suggested that the normally linear fluorescent tube be bent into a substantially U- shape configuration. With this type of lamp configuration, there is a need for some relatively simple mechanical device which will support the based ends of the lamp firmly and securely a precise predetermined distance from one another.

One device which has been suggested asa means for joining the based-ends of a Ushaped lamp to one another has been a two-piece strap wrapped tightly around the periphery of the two bases to provide a frictional bond and then welded together to form a unit. However, this arrangement is characterized by certain disadvantages which make it somewhat less than satisfactory. For example, the tightness of the strap required to maintain a secure frictional bond with the lamp bases causes a compressive force to be exerted on the bases and the end portions of the lamp disposed therein great enough to snap off the ends from the main body of the lamp envelope at the baseline. On the other hand, if the strap is relatively loose, it might well slide off one or both bases and thus lose its effectiveness.

In view of the foregoing, one of the principal objects of this invention is to provide a device for joining the based ends of a U-shaped lamp to one another in such a way that there is no need for the application of excessive forces to the bases and the end portions of the lamp disposed therein.

Another object is to provide such a device which will also automatically prealign the pins of the two bases with each other.

A further object is to provide such a device which is relatively simple in construction, relatively cheap in cost and inexpensive toassemble.

These and other objects, advantages and features are attained, in accordance with the principles of this invention, by providing each lamp base with a notch formed in the peripheral edge thereof and aligned in a predetermined orientation with respect to the base pins. The notched bases are connected to one another by a rod having a circumferential groove or notch formed therein near each end thereof, with the grooved ends of the rod interlocking in the notched peripheral edges of the bases. The bases, connected to one another by the rod, are placed on the ends of the lamp and baked in place in the conventional manner. In this operation some of the basing cement flows around the ends of the rod thus securing it in position and joining the ends of the lamp to one another in a unitary arrangement.

In the specific embodiment of the invention illustrated in the accompanying drawing, FIG. 1 isa plan view of a lamp provided with the base assembly of this invention.

FIG. 2 is an exploded detail of the components of the base assembly of this invention.

FIG. 3 is a fragmentary detail in section and on an enlarged scale of an end of the lamp of FIG. 1 and taken along the line 3-3 thereof.

Referring now to the drawing, the lamp 2 of FIG. 1 is a conventional linear 40 watt fluorescent tube bent into a substantially U-shaped configuration. As shown particularly in FIG. 3, the lamp 2 comprises a tubular envelope 4 having a coating of fluorescent material 6 on the inner wall thereof. A lamp mount 8, a fragmentary portion of which is shown here, is

sealed in each end of the tubular envelope 4. Each end of the lamp envelope 4 is provided with a neck orv collar I0 to WhlCh a base 12 is secured by basing cement 14. The base 12 includes a pair of electrical contact pins 16 to which lead-in wires 18 from the mount 8 are connected.

As shown in FIG. 2, the base assembly of this invention comprises a pair of bases 12 and a connecting rod 20. The bases 12 may be conventional except that each of them is provided with a notch 22 formed in the peripheral edge thereof with the center line of the notch being-aligned with the center line of the base pins I6. The connecting rod 20 is provided with a circumferential groove or notch 24 formed therein near each end thereof. The location of these grooves in the rod insures the accurate positioning of the bases to the desired centerline-to-centerline dimension.

The entire assembly operation is quite simple. A pair of bases 12, each having a ring of basing cement 14 located therein, are located in spaced relationship with respect to one another and with the notches 22 aligned with one another. The rod 20 is then dropped in place with the circumferential grooves formed in the ends thereof interlocking with the notches in the bases. This base assembly is then united with a substantially U-shaped tubular envelope 4 by placing the bases on the ends of the lamp envelope. The basing cement 14 is then cured in the usual manner to thereby securely affix the bases to the ends of the lamp envelope. In so doing, the basing cement 14 tends to flow around the ends of the connecting rod located within the bases thereby securing it against subsequent movement.

Although the foregoing assembly method is preferred, it will be readily apparent to one skilled in the art that alternative techniques may be employed. For example, the connecting rod or member could be welded to the skirt of the bases, or it could be secured thereto by riveting or by an epoxy cement without departing from the spirit and scope of the invention.

Iclaim:

l. A unitary base assembly for an elongated tubular lamp, the ends of which lie in substantially the same plane, said assembly comprising a pair of lamp bases, a rod located therebetween, and means for connecting said rod to said lamp bases, said means comprising a notch fonned in the peripheral edge of each of said bases and a cooperating circumferential groove formed near each end of said. rod.

2. A unitary base assembly for an elongated tubular lamp, the ends of which lie in substantially the same plane, said assembly comprising a pair of lamp bases, a .rod located therebetween, and means for connecting said rod to said lamp bases, said means comprising a notch formed in the peripheral edge of each of said bases and a cooperating notch formed near each end of said rod.

3. A lamp assembly comprising: a tubular envelope bent into a substantially U-shaped configuration with the ends thereof lying in substantially the same plane; a base secured to each of the ends of said envelope; and rod means for connecting said bases to one another, said bases being provided with basing cement and said basing cement securing said bases to said lamp envelope and also securing said connecting rod.

4. The combination of claim 3 in which said bases are provided with notches formed in the peripheral edges thereof and said connecting rod is provided with cooperating circumferential grooves formed near each end thereof. 

1. A unitary base assembly for an elongated tubular lamp, the ends of which lie in substantially the same plane, said assembly comprising a pair of lamp bases, a rod located therebetween, and means for connecting said rod to said lamp bases, said means comprising a notch formed in the peripheral edge of each of said bases and a cooperating circumferential groove formed near each end of said rod.
 2. A unitary base assembly for an elongated tubular lamp, the ends of which lie in substantially the same plane, said assembly comprising a pair of lamp bases, a rod located therebetween, and means for connecting said rod to said lamp bases, said means comprising a notch formed in the peripheral edge of each of said bases and a cooperating notch formed near each end of said rod.
 3. A lamp assembly comprising: a tubular envelope bent into a substantially U-shaped configuration with the ends thereof lying in substantially the same plane; a base secured to each of the ends of said envelope; and rod means for connecting said bases to one another, said bases being provided with basing cement and said basing cement securing said bases to said lamp envelope and also securing said connecting rod.
 4. The combination of claim 3 in which said bases are provided with notches formed in the peripheral edges thereof and said connecting rod is provided with cooperating circumferential grooves formed near each end thereof. 